Algae, including red, brown and green algae commonly known as seaweeds, are the primary producers of the marine environment which covers approximately 70% of the earth's surface. In addition, seaweeds yield unique biochemical substances which may be pharmacologically active, for example as vital inhibitors or cell division inhibitors, and substances which can serve as gelling and thickening agents. Cell walls which encase the cell body of algae and higher plants, create obstacles to the use of plant cells in procedures such as the introduction of foreign DNA for transformation into the cells, and somatic hybridization in which sexually unrelated cells may be united to create a new, combined genome.
Protoplasts, which are cells with the cell wall removed, are thus useful for various genetic manipulations of the plant cell, including those which may be used to attempt to improve the characteristics of the whole plant. In particular, seaweed protoplasts may provide a means to study the basic biology of algal cells including cell physiology, biochemistry, cell wall development and plant differentiation, and may be useful in seaweed cultivation (aquaculture). It has been particularly difficult to isolate protoplasts from seaweeds due to the nature of the cell wall which is composed largely of complex sulphated polysaccarides, and because of the commercial unavailability of enzymes effective in degrading these complex molecules. In general, attempts to isolate protoplasts from higher plants have used techniques where the plant is then placed in solutions containing fungal or bacterial enzymes for several hours. Released protoplasts are collected using density gradients or by the use of separating devices such as nylon screens. In other procedures, soft seaweed tissues are treated with sea snail intestinal enzymes and have been ground to release protoplasts using a tissue homogenizer. These methods are inefficient and tedious, yielding low numbers of protoplasts, many of which are damaged by the procedure used to obtain them.
Microorganisms which can efficiently digest cell walls, would thus be highly useful.
Pollution of the ocean with plastic wastes, particularly those materials composed of complex hydrocarbons, including halogenated hydrocarbons, causes harm to marine life, which if not controlled, may rise to the level of that caused by oil spills and toxic chemical waste. While plastics, which are generally not biodegradable, are fast replacing biodegradable natural packaging materials, there has not been a corresponding development of methods for degrading plastic. Thus the accumulation of plastic wastes poses a continuing problem. In addition, the plastic manufacturing industry produces a variety of by-products during the production of plastics including polyvinyl chloride and polyvinylidin di-chloride, which must then be disposed of. There is a need for a method to degrade these by-products rather than introducing them into the environment where they may contribute to the pollution problem.
Biological processes are being increasingly employed in industry to combat pollution. In particular, microorganisms are being developed to degrade pollutants. It would therefore be advantageous to develop microorganisms capable of degrading plastics.